This proposal seeks a Fogarty International Research Collaboration Award (FIRCA) to support joint work between Douglas S. Massey of the University of Pennsylvania and Rene Zenteno of the Guadalajara Campus of the Instituto Tecnologico de Estudios Superiores de Monterrey. Its specific aims are: to evaluate the efficacy of adapting ethnosurvey questions to standard demographic surveys and to evaluate the possibility of adding them to future representative samples of Mexican urban labor markets; to measure the potential biases incurred by the use of non-representative ethnosurvey methods rather than representative sampling methods in studying Mexican out-migration to the United States; to study processes of international migration emanating from the Mexico-U.S. border region, thus broadening the base of empirical generalization over prior work; to measure the level of daily commuting for work in the United States-both legal and illegal-by Mexican border residents and to compare the causes and consequences of border commuting with those of long-distance migration; and to document the incidence and range of U.S. migratory experience present in the Mexican population using nationally representative data, and to discern trends in the geographic and socioeconomic selectivity of Mexico-U.S. migration over time. These goals will be accomplished by systematically comparing analyses of data obtained from the Tijuana administration of Mexico's National Survey of Urban Employment (NSUE) with information drawn from the Mexican Migration Project's (MMP) recent round of surveys in the same city, and by replicating earlier work based on the MMP using nationally-representative data from Mexico's Retrospective Demographic Survey. If our comparison of MMP and NSUE data in Tijuana is successful, and suggests the efficacy both of using ethnosurvey items on standard surveys and of combining the two approaches in a single analysis, we plan to implement this basic design in other cities throughout Mexico.